Shrinkable compression rings are known in the art which, for the most part, have been made by cutting off rings from tubular stock of various materials. These rings were compressed or shrunk by various means, such as mechanical means, magnetic means, hydraulic means, etc.
The use of such compression rings has recently gained importance by the availability of so-called puzzle-lock clamping or compression rings made from band material, i.e., compression rings with a mechanical connection of the free ends thereof resembling a puzzle-lock as disclosed in my prior U.S. Pat. Nos. 5,001,816 and 5,185,908 which permitted the use of flat band material for the manufacture of such compression rings. However, to satisfy markets such as the automotive industry, it is necessary to provide machines capable of automatically mass-producing these so-called puzzle-lock compression rings.